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I (Model.) I C. B. OSBORN.

GAGE.

No. 299,843. Patented June 3, 1884.

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UNITEDv STATES PATENT OFFICE.l

CHARLES B. OSBORN, OF OANANDAIGUA, NEV YORK.

GAGE.

SPECIFICATION forming part of Letters Patent No. 299,843, dated June 3,1884.

Application filed April 12, 1884. (Model.)

To all whom t mayconoern:

Be it known that I, CHARLEs B. OsBoRN, a citizen of the United States,residing at Canandaigua, in the county of Ontario and State of New York,have invented certain new and useful Improvements in Dado Guides forPlanes; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to letters or gures of referencemarked thereon, which form a part of this speeication.

Figure 1 of the drawings is a face View of my device. Fig. 2 is avertical sectional view of the same, and Fig. 3 is a transverse section.

This invention has relation to adjustable guides for dado-planes; and itconsists in the construction and novel arrangement of thelongitudinally-recessed rule, carrying a slotted guide-plate and cam,the slotted extensionbar engaging the guide-plate, a secondradially-adjustable clamp-jaw, pivoted to said eX- tension-bar, anddevices for holding the extension-bar and clamp-jaws in position. afteradjustment, substantially as specified.

In the accompanying drawings, the letter A designates the rule orguide-bar, against which the dado-plane is designed to work. In thebottom of this bar is made a longitudinal recess, B, and it is providedwith an under faceplate, O, which is longitudinally slotted at D, belowthe recess of the bar. The lateral margins of the slot D proj ectinwardly beyond the walls of the recess, to form slide-guides E for theextension.

F indicates the rear clamp-jaw, which is connected to the rule near itsend by a clampscrew and a pivot, G, which engages a spring, H, in arecess of the rule, giving a little play to the clamp-bar in thedirection of the length of said rule. The clampscrews K pass througha.,strap, L, and through slots I, which are extended radially in seriesaround the center of the jaw. When the clamp-screws are loosened, thejaw can be turned to the required angle, and then by turning theclamp-screws it can be held atthat angle firmly. The biting or holdingedge N of the jaw, which is to be pressed against the work, ispreferably provided with small teeth a. The slots through which theclamp-screws pass are diametrically opposite to each other, and allowthe 'clampjaw to be pressed back a little by the spring.

4which engages the circular back b of the clamp-jaw. Vhen this cam isturned in the proper direction, it will force the jaw forward againstthe work. The slide bar or extension V is slotted in its sides, orentirely through from side to side, as indicated at R, to engage theguide-edges E of the slotted plate C. This extension is designed to fillthe recess of the rule-bar neatly, but so that it will slide easily inits bearing.

Z represents the clamp-jaw, which is pivoted to the inner end of theextension by the clamp-screw S, which engages a nut, T, under theslotted guide-plate C. IVhen the clampscrew S is turned up hard, itsecures the eX- tension-bar in the position to which'it has beenadjusted with relation to the rule-bar. The clamp-jaw Z is usuallyprovided with small teeth, and is slotted, as at c, to receive aclamp-screw, J, whereby said jaw is held iirmly in position after itsangular adjustment.

In operating this device the clamp -screw S is loosened, and the jawsare adjusted to the proper angle for the work, which is received betweenthem. The extension-bar and `its jaw are then fastened up to the work,allowing about a quarter of an inch between the edge of the jaw and thework. Then the clamp-screw S is tightened and the cam l? is turnedforcibly, acting to press the jaws against the work. The rule is' nowfixed in position to guide the dado.

Having described this invention, what I claim, and desire to secure byLetters Patent, 1s-

A dado-guide consisting of the longitudinally-recessed rule, carrying aslotted guideplate, a radiallyadjustable clamp-jaw, and

mam, the slotted extension-bar engaging the guide plate, a secondradially adjustable clamp-jaw pivoted to said extension-bar, and devicesfor holding the extension-bar and clamp-jaws in position afteradjustment, substantially as specified.

In testimony whereof I aiiix my signature in presence of two witnesses.

CHARLES B. OSBORN.

Vitnesses:

' G. GRANGER BENHAM,

BRADLEY WYNKoor.

In rear of the clamp-j aw is pivoted a cam, I),

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